The Desert Tortoise and Cattle Grazing: A Historical Perspective

The article by Vernon Bostick, published in RANGELANDS in June 1990 ( https://reallibertymedia.com/the-desert-tortoise-in-relation-to-cattle-grazing ), challenges the then-prevailing notion that cattle grazing negatively impacts desert tortoise populations. It argues that historical evidence suggests a counter-intuitive relationship: desert tortoise populations thrive in areas with cattle grazing and decline when cattle are removed.

Historically, desert tortoises have coexisted with cattle in the southwestern US and Mexico for centuries. Despite periods of severe overgrazing by livestock in the late 1800s and early 1900s, desert tortoise populations not only survived but, according to some accounts, reached exceptionally high densities. For example, Dr. Kristin Berry's research indicates densities as high as 2,000 tortoises per square mile in 1933, a time of drought and extensive overgrazing.

The author posits that the tortoise's primary food source is dung, specifically from other animals like cattle, rabbits, deer, and bighorn sheep This allows them to avoid consuming the often low-quality, fibrous plant material that other grazers compete for, especially during droughts. The more animals on the range, the more dung is available, providing a consistent and nutritious food source for tortoises.

The article highlights the Taylor Grazing Act of 1934, which aimed to regulate and reduce livestock grazing on public lands. While intended to restore degraded rangelands, the author argues that this reduction in cattle numbers has correlated with a decline in desert tortoise populations.

Case studies from Beaver Dam Mountains in Utah and the Nevada Test Site further support this claim. In areas where cattle have been excluded for extended periods, tortoises have shown signs of malnutrition and poor health, including osteoporosis due to insufficient protein. Conversely, tortoises in areas open to cattle grazing appear healthy and well-nourished.

In conclusion, the article asserts that:

• Desert tortoises have a long history of coexisting with cattle.

• The highest known tortoise densities occurred during periods of severe livestock overgrazing.

• Fewer cattle on the range lead to fewer tortoises.

• Excluding cattle can endanger tortoise populations.

Bostick suggests that while overgrazing by one species can degrade a range for that species, it can improve the habitat for another, such as the desert tortoise, which thrives on the by-products of grazing animals. The decline in tortoise numbers since the Taylor Grazing Act is presented as a direct consequence of decreased livestock grazing and "improved" range conditions that are, in fact, detrimental to the tortoise's unique dietary needs.

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